Picoscale thin layer chromatography for analysis of single cells and microsamples

Abstract

Thin layer chromatography (TEC) devices for the analysis of pico-scale samples, methods for using the devices, and methods for fabricating the devices.

1 . A thin layer chromatographic (TLC) device, comprising a non-porous substrate having one or more microchannels formed on its surface, each microchannel comprising a porous, exposed, substantially homogeneous microband adapted for fluid flow driven by capillary action. 
     
     
         2 . The device of  claim 1 , wherein the porous microband is a monolithic porous silica microband. 
     
     
         3 . The device of  claim 1 , wherein the fluid flow is capillary fluid flow combined with electrophoresis. 
     
     
         4 . The device of  claim 1 , wherein the fluid flow is capillary fluid flow driven by intermolecular forces. 
     
     
         5 . The device of  claim 1 , wherein the fluid flow is not driven by hydrodynamic centrifugal force or pressure-driven fluid flow. 
     
     
         6 . The device of  claim 1 , wherein the microchannel is in the non-porous substrate surface or formed on top of the non-porous substrate followed by cladding laterally with non-porous walls. 
     
     
         7 . The device of  claim 1 , wherein the microchannel is straight or curved. 
     
     
         8 . The device of  claim 1 , wherein the porous microband has a width from about 1 to about 1000 μm. 
     
     
         9 . The device of  claim 1 , wherein the porous microband has a depth from about 1 to about 100 μm. 
     
     
         10 . The device of  claim 1 , wherein the porous microband has a length substantially co-terminous with the length of the device. 
     
     
         11 . The device of  claim 1 , wherein the porous microband has an aspect ratio (width/depth) from about 1 to about 100. 
     
     
         12 . The device of  claim 1 , wherein the porous microband has a cross-sectional area from about 10 μm 2  to about 50,000 μm 2 . 
     
     
         13 . The device of  claim 1 , wherein the substrate is glass, quartz, plastic, polymer, ceramic, metal, or silicon. 
     
     
         14 . The device of  claim 1 , wherein the device comprises a single microchannel comprising the porous, substantially homogeneous microband. 
     
     
         15 . The device of  claim 1 , wherein the device comprises from two to about 1,000,000 microchannels, each microchannel comprising the porous, substantially homogeneous microband. 
     
     
         16 . A method for fabricating a thin layer chromatography device, comprising;
 (a) forming one or more microchannels in a non-porous substrate;   (b) forming a fully enclosed microchannel using a detachable sealing material;   (c) filling the one or more enclosed microchannels with a flowable porous microband precursor composition;   (d) subjecting the non-porous substrate having one or more microchannels filled with a flowable porous microband precursor composition to conditions to that convert the composition to a porous microband; and   (e) detaching the sealing material to expose the porous microbands to provide a thin layer chromatography device.   
     
     
         17 - 31 . (canceled) 
     
     
         32 . A method for thin layer chromatography of the contents of a single cell, a group of cells, or a microsample using the device of  claim 1 . 
     
     
         33 - 34 . (canceled) 
     
     
         35 . The method of  claim 32 , wherein the contents are biological analytes selected from the group consisting of fatty acids, amino acids, peptides, lipopeptides, vitamins, hormones, proteins, carbohydrates, enzyme substrates, and metabolites. 
     
     
         36 . A method for thin layer chromatography of analytes in a sample having a volume from about 1 zL to about 100 nL using the device of  claim 1 . 
     
     
         37 . The method of  claim 36 , wherein the analytes are fatty acids, amino acids, peptides, lipopeptides, proteins, carbohydrates, metabolites, hormones, antigens, pollens, spores, vitamins, cytokines, indoles, antibiotics, pigments, steroids, phenols, bile acids, coumarins, pharmaceuticals, reaction analytes, toxins, pesticides, insecticides, poisons, or pollution contaminants. 
     
     
         38 - 46 . (canceled)